A computer may act as a virtual machine, e.g., the computer may emulate the configuration of a computer that is different from the server's configuration. For instance, a host server having Linux as its operating system may run a program that emulates a server that boots and runs a Windows operating system and Windows-compatible applications. That same server may subsequently or simultaneously run a program that emulates a personal computer that boots and runs MAC OS and MAC OS compatible applications.
The identical virtual machine may be used on multiple host computers or at different times. In such regard, the virtual machine may be loaded into the memory of the host computer and booted, and a snapshot image of the memory may be stored for future use on the same or other computers. When a virtual machine having the same characteristics is required, the image may be loaded directly into the host computer, e.g., from disk storage, instead of booting the machine from scratch.